21890708164 has 24 divisors (see below), whose sum is σ = 41350886360. Its totient is φ = 10080059904.

The previous prime is 21890708131. The next prime is 21890708173. The reversal of 21890708164 is 46180709812.

It can be written as a sum of positive squares in 4 ways, for example, as 761760000 + 21128948164 = 27600^2 + 145358^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 463599 + ... + 508630.

Almost surely, 2^21890708164 is an apocalyptic number.

It is an amenable number.

21890708164 is a deficient number, since it is larger than the sum of its proper divisors (19460178196).

21890708164 is a wasteful number, since it uses less digits than its factorization.

21890708164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972679 (or 972677 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 46.

The spelling of 21890708164 in words is "twenty-one billion, eight hundred ninety million, seven hundred eight thousand, one hundred sixty-four".